What kind of life does the Gospel call for? Paul spells it out in Romans 12:1: “THEREFORE, I urge you, brethren, by the mercies of God, that you present your bodies a sacrifice.” In these words, Paul is summarizing the proper response to the Gospel. Everything that comes after this in the book of Romans is simply an exposition of the details of this commitment: Present your bodies a sacrifice.

So what does it mean? Here in verse 1, Paul is using the same vocabulary that the Septuagint uses for the sacrifices of the Old Testament Law. (In case you don’t know, the Septuagint is the Greek translation of the Old Testament that was the everyday Bible of Paul’s day. So Paul is intentionally using the image of Old Testament sacrifices to describe this New Testament sacrifice.

The word present here is the word the Old Testament uses for placing an animal on the altar, for making it an offering to God. The word sacrifice is the word the Old Testament uses for the animal itself. But here in Romans, it’s not a lamb or a bull; rather, it’s our own bodies. So in the Old Testament, the body of an animal was presented to God as a sacrifice. In the New Testament, we are called to present our own bodies as a sacrifice. The animal on the altar is you.

Fortunately, the sacrifice Paul is describing is unusual in another way: it’s living. That’s the difference between this New Testament sacrifice and Old Testament sacrifices: Those were offered to God having been killed; these are offered to God alive.

And that is where the concept of availability comes in. The key is in the word holy, which means completely set apart to God. Animals were killed and burned in order to be completely set apart to God. They could no longer belong to the one who gave them; they belonged entirely to God. So to present my body as a sacrifice, living and holy, is to make it available to God exclusively. It is his to do with as he wishes; it is no longer mine or anyone else’s.

This is what Jesus was talking about when he required his disciples to deny themselves and take up their crosses daily, and follow him. This is what Paul was talking about when he said, “Therefore, it is no longer I who live, but Christ lives in me, and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.”

All of the language of Romans 12:1 supports the idea that the very essence of the Christian life is this sort of radical availability. The word present literally means to place something at someone’s disposal. The concept of the body carries the idea of availability, also. Paul is not saying, “Give your body to God, but you can keep your heart, soul, and mind.” Instead he’s simply referring to the fact that your body is the aspect of your existence that makes you available to others—the way in which you are one place or another, with one person or another.

Paul is doing battle with the Greek philosophers and gnostics, who thought that the body was an obstruction to anything truly spiritual and good. Paul says no. The proper Christian life is an embodied life. The whole human being—body, soul, and spirit—is created in the image of God. The Christian life is not to be over-spiritualized in the sense that it might be considered entirely mystical or mental. The ultimate state for the Christian is life in a resurrected, physical body. We do not seek escape from the body; instead, we are called to present our bodies to God for his service. When we offer our bodies, our hearts, souls, and minds are included in the deal. This is especially evident in Paul’s use of the word living. A body without a spirit would no longer be living.

So this New Testament sacrifice is a life of radical availability to God, a life lived solely as an extension of the life of Christ, a life under the exclusive control of the Holy Spirit, a life that does not belong to the one who lives it.